Turbo Dodge HelpUrgent help when something goes wrong with your Dodge and you can't figure out what the problem is. Troubleshooting help and the place to post when you're stuck with a broken car and have to get to work the next day.

bought the car at auction as-is.
They assured us it had a bad crank position sensor.

We have replaced with new parts the crankshaft sensor, Camshaft sensor, coil wires, plugs, and with used parts the computer (on the firewall). as far as we know the engine has not been opened up nor has the timing belt. timing belt does look good, snug and turns. compression is good.

We have power going to the green/orange wire on the coil. nothing on the other two wires (blue/yellow & brown/yellow), and no spark comming out of the coil. it does have fuel pressure. No codes saved on computer (probably cause it had a dead battery at auction). all fuses are good.

unfortunately i'm am not very familiar with the 2.4L motors so any help and diagrams would be greatly appreciated.

It's official! We have become a dodge family.
My parents both cruise in caravans now

also like i said i DO have 12V to the coil power wire (the green/orange)

but there is nothing in the other two signal? wires.

so if there is no signal going to the coil.. that would indicate a possible computer problem.. correct?

But what tells the compter to send those signals? is it the cam sensor?

and how can i test to make sure the computer is recieving the signals but not transmitting them to the coil? so that i may determine if the problem lies in the computer or to the device sending info to the computer.

any wiring diagrams would be most helpful. especially a computer plug pin chart.

also is there another computer on the vehicle besides the one on the firewall? and is there any safety shutoff / shutdown circut that may be active and causeing this problem? (ie. like the fuel shut-off switches on fords)

and lastly.. how can i test the camshaft position sensor to make sure it is sending the signal properly.

thanks again.

It's official! We have become a dodge family.
My parents both cruise in caravans now

I will check "Tech Authority" tonight and get back with you.
Couple of questions....
Does this car have SKIM(Security Key Immobilization Module)?
If it does the key will be Grey and the security light will be flashing on the dash.
Do you have an OBD2 scanner?
If so are the BUS lines ok and all controllers are communicating?
If not there will be "U codes" stored, you can only retrive them with a scanner.

You use Chrysler sensors or aftermarket? Many have found there are bad aftermarket sensors.
How many miles on it? The timing belt may have jumped some teeth....
It is rare for the coils to go bad, but no voltage out of coil?
For more help, try here: General Forums - PT Cruiser Forum

I will check "Tech Authority" tonight and get back with you.
Couple of questions....
Does this car have SKIM(Security Key Immobilization Module)?
If it does the key will be Grey and the security light will be flashing on the dash.
Do you have an OBD2 scanner?
If so are the BUS lines ok and all controllers are communicating?
If not there will be "U codes" stored, you can only retrive them with a scanner.

It does have a grey key but i did not notice any light, I also took a good look around for any aftermarket alarms, there are none.
i only have a cheap read/test actuators/clear obdII scanner no codes whatsoever. i will try a test today.

You use Chrysler sensors or aftermarket? Many have found there are bad aftermarket sensors.
How many miles on it? The timing belt may have jumped some teeth....
It is rare for the coils to go bad, but no voltage out of coil?
For more help, try here: General Forums - PT Cruiser Forum

we replaced with aftermarket that's why i was asking how i could test them.
coil outputs nothing (i'm sure because there is no signal going to it to fire)

If you have a Grey key you already have an issue but it will not create a no spark condition, it will create a start and stall after 3 seconds when the controller shuts down the fuel system.
The "secret pin #" for the SKIM system is programmed into the PCM and the SKIM module verifies the PIN against the Pin in the key transponder each time it is placed in the ignition.
If you replaced the PCM and did not "flash" it for your vehicle your SKIM info and VIN info will be incorrect.
Chrysler is not showing anything related to ignition for a no start without codes.
They are saying that any "cranks but will not start" not related to fuel pressure issues will set fault codes.
The vehicle operates on the same principal as out TD's.
The controller needs to see a Crank and Cam signal before it will actuate the ASD.

CAMSHAFT POSITION SENSOR - 2.4L
DESCRIPTION
The camshaft position sensor is mounted to the rear of the cylinder head. The sensor also acts as a thrust plate to control camshaft endplay Target Magnet - Typical

OPERATION
The PCM sends approximately 9 volts to the Hall-effect sensor. This voltage is required to operate the Hall-effect chip and the electronics inside the sensor. The input to the PCM occurs on a 5 volt output reference circuit. A ground for the sensor is provided through the sensor return circuit. The PCM identifies camshaft position by registering the change from 5 to 0 volts, as signaled from the Camshaft Position sensor.

A target magnet attaches to the rear of the camshaft and indexes to the correct position. The target magnet has four different poles arranged in an asymmetrical pattern. As the target magnet rotates, the camshaft position sensor senses the change in polarity Target Magnet Polarity

The PCM determines fuel injection synchronization and cylinder identification from inputs provided by the camshaft position sensor Camshaft Position Sensor - 2.4L DOHC and crankshaft position sensor. From the two inputs, the PCM determines crankshaft position.

The sensor input switches from high (5 volts) to low (0.30 volts) as the target magnet rotates. When the north pole of the target magnet passes under the sensor, the output switches high. The sensor output switches low when the south pole of the target magnet passes underneath.

CRANKSHAFT POSITION SENSOR - 2.4L
DESCRIPTION
The crankshaft position sensor mounts to the engine block below the generator and near the oil filter Crankshaft Position Sensor

OPERATION
The PCM sends approximately 9 volts to the Hall-effect sensor. This voltage is required to operate the Hall-effect chip and the electronics inside the sensor. A ground for the sensor is provided through the sensor return circuit. The input to the PCM occurs on a 5 volt output reference circuit that operates as follows: The Hall-effect sensor contains a powerful magnet. As the magnetic field passes over the dense portion of the counterweight, the 5-volt signal is pulled to ground (.3 volts) through a transistor in the sensor. When the magnetic field passes over the notches in the crankshaft counterwieght, the magnetic field turns off the transistor in the sensor, causing the PCM to register the 5-volt signal. The PCM identifies crankshaft position by registering the change from 5 to 0 volts, as signaled from the Crankshaft Position sensor.

The PCM determines what cylinder to fire from the crankshaft position sensor input and the camshaft position sensor input. The second crankshaft counterweight has machined into it two sets of four timing reference notches including a 60 degree signature notch Timing Reference Notches - Typical From the crankshaft position sensor input the PCM determines engine speed and crankshaft angle (position)

The notches generate pulses from high to low in the crankshaft position sensor output voltage. When a metal portion of the counterweight aligns with the crankshaft position sensor, the sensor output voltage goes low (less than 0.5 volts) When a notch aligns with the sensor, voltage goes high (5.0 volts) As a group of notches pass under the sensor, the output voltage switches from low (metal) to high (notch) then back to low.

ELECTRONIC IGNITION COIL - 2.4L
WARNING: THE DIRECT IGNITION SYSTEM GENERATES APPROXIMATELY 40,000 VOLTS. PERSONAL INJURY COULD RESULT FROM CONTACT WITH THIS SYSTEM.

OPERATION
High tension leads route to each cylinder from the coil. The coil fires two spark plugs every power stroke. One plug is the cylinder under compression, the other cylinder fires on the exhaust stroke. Coil number one fires cylinders 1 and 4. Coil number two fires cylinders 2 and 3. The PCM determines which of the coils to charge and fire at the correct time.

The Auto Shutdown (ASD) relay provides battery voltage to the ignition coil. The PCM provides a ground contact (circuit) for energizing the coil. When the PCM breaks the contact, the energy in the coil primary transfers to the secondary causing the spark. The PCM will de-energize the ASD relay if it does not receive the crankshaft position sensor and camshaft position sensor inputs.

AUTOMATIC SHUTDOWN RELAY
DESCRIPTION
The ASD relay is located in the PDC Power Distribution Center (PDC) The inside top of the PDC cover has a label showing relay and fuse identification

The PCM controls the ASD relay by switching the ground path for the solenoid side of the relay on and off. The PCM turns the ground path off when the ignition switch is in the Off position unless the O2 Heater Monitor test is being run. Refer to the On-Board Diagnostics in the Emission Control section. When the ignition switch is in On or Start, the PCM momentarily turns on the ASD relay. While the relay is on the PCM monitors the crankshaft and camshaft position sensor signals to determine engine speed and ignition timing (coil dwell) If the PCM does not receive crankshaft and camshaft position sensor signals when the ignition switch is in the Run position, it will de-energize the ASD relay

thanks a ton for that info & pics i'll let u know how it goes. another mechanic worked on it previously & gave up.. i'll need to find out what happened to the origional computer. i found mouse chewed wires under the power box under the hood... chances are they shorted out both computers and maybe more. I repaired the wires & now i'm going to test signals.

BTW what is the component on the rear bank of the head? CMP sensor is on the front... there is another small 1 wire component on the right rear with the same power lead as the coil. it's soaked in oil also.

last question for now is what kind of signal/voltage should be sent from the PCM to the coil? These are the brown/yellow & blue/yellow wires at pins 3 and 11 that run to the coil.

also since i have not taken a good look at the PCM, if there are not any marks on the 2 plugs to the pcm as to pin numbers how do i know which pin is which?... if there are marks obviously ignore that question lol. the vehicle is not at my home so i will find out in an hour.
should they also be 5 & 0 volts?

It's official! We have become a dodge family.
My parents both cruise in caravans now

ok so after some testing with my multimeter, the computer is not sending any pulses to the coil from pins 3 and 11. the CMP is working properly. the CKP i am un sureabout.

pin 32 shows 5v at all times with the power on. no pulses. power off it shows .4 .

it seems that the PCM is backfeeding the 5V as when the sensor is unplugged and i check the sensor end for voltage i get 5v from the grey/black wire from the PCM at power on at all times... this shows that the 5v at pin 32 is comming from the PCM. so at this point i'm stuck between the CKP sensor and the PCM being most likely the problem causers. i spoke to the previous mechanic & they said they put the origional PCM back in after the new one failed to work. therefore the key which IS grey should not be an issue. I am still getting no codes either.

how else can i test the CKP sensor? should i cut the grey/black wire to prevent feedback from the PCM?
and how can i test the PCM?

i still believe the PCM may be bad because as i said earlier mice had eaten the wires under the under-hood fuse panel and caused shorts. i have fixed all the eaten wires a few days ago but i believe if they were shorted they may have also affected the new PCM that they tried.

so where do i go from here? should i try another CKP? or try a PCM? and or what other tests can i do?

also the CKP sensor has 3 wires to it the orange (which i guess is the feed) shows 8V the middle wire shows nothing and i believe is the part the the PCM uses to determine engine speed. and has no significance to this problem. correct?

thanks again for the help

It's official! We have become a dodge family.
My parents both cruise in caravans now

These cars are a PITA to diagnose without a DRB3, you will be doing alot of "shooting in the dark".
I work on Jeeps and the 3.7/4.7L engines are basically the same system but I have access to all Chrysler scanners so I have never had to do this without a scanner.
I can send you the diagnostics for coil issues with a fault code which may help.
I can also send you the connector pinouts for the PCM.
You will have to let me know as you go along if you need other wiring or info, be sure you check all of the PCM power feeds and grounds.
The problem with the wiring is it is no longer setup as is was for a TD, one circuit may have 10 different wiring pages.

Ive had a pt cruiser give me problems like this. well to start all wiring between coil and pcm good? second the pcm grounds the coil drivers driver #1 and #2, is there no spark at all present? I had one with a similar issue where very little spark would be present and it ended up being the coil and in some cases the coil could burn up the pcm. Good Luck!

Ive had a pt cruiser give me problems like this. well to start all wiring between coil and pcm good? second the pcm grounds the coil drivers driver #1 and #2, is there no spark at all present? I had one with a similar issue where very little spark would be present and it ended up being the coil and in some cases the coil could burn up the pcm. Good Luck!

there is no spark whatsoever from the coil. only a pulse to the feed from the ASD

i read a post on another forum stating that the driver wires should recieve a 5v pulse from the PCM... you are saying that the PCM should be grounding these pulses from the coil? so a continuity test from those wires to the ground, plug disconnected from the coil should should show that correct? and likewise plugged in, the 5V passing from the coil to the PCM should also show on those as wires as a 5V pulse from the coil. I believe when i tested it there was a contant 5V comming from the coil to the PCM on both of those lines. i will have to check it again on friday. but if there is no pulsing from the coil... what does that mean?

lol sadly to say now that i look at the diagram from before that does make sence. maybe I will luck out and it's just a coil.

It's official! We have become a dodge family.
My parents both cruise in caravans now

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